This invention relates to a poultry feeder for feeding birds raised in a poultry house where feed is supplied to a multiplicity of feeders by means of a feed conveyor conveying feed from a bulk feed tank or the like located outside the house to the feeder. Typically, such poultry houses will confine tens of thousands of birds. In the case of chickens, day old chicks are introduced into the house and are raised in the house throughout the growth cycle until ready for market. In the case of turkeys, the birds may be moved from house to house as the birds grow from chicks to poults to adult birds.
There has been a long-standing need for a poultry feeder, particularly for larger birds such as larger turkey poults and adult turkeys, which presents a minimum quantity of feed in the feed pan so as to prevent spoilage or wastage of the feed, but which continuously replenishes this smaller supply of feed in the feed pan between operating cycles of the feed conveyor. There has also been a need for such a feeder that can discharge greater quantities of feed into the feed pan, (sometimes referred to as flooding the feed pan), particularly upon introduction of the younger birds in the house so that the younger birds may more readily see the feed in the feed pan of the feeder and may have more ready access to the feed and then change to the above-described lesser quantity of feed presented in the feed pan as the birds grow in size. There has also been a need for a truly "grill-less" feeder which has no obstructions in the feed pan which may take up space and thus inhibit the birds from eating or which may prevent the maximum number of birds from eating from the feed pan.
Reference may be made to U.S. Pat. No. 4,476,811 which shows a poultry feeder having a drop tube affixed to a feed conveyor tube for receiving feed therefrom. Upon the introduction of small chicks into the poultry house, this feeder is adjusted to discharge the feed from so-called flood windows located in the drop tube considerably above the level of the feed pan. In this manner a large quantity of feed is dispensed into the feed pan so as to flood the feed pan thus enabling the small chicks to see the feed and to consume the feed. Upon the chicks growing in size, the feeder is changed from the above-described flood condition in which feed is dispensed from the flood windows, to a normal feeding condition in which the flood windows are closed or blocked and in which feed is dispensed from the open bottom end of the drop tube so as to present a small quantity of feed within the feed pan. U.S. Pat. Nos. 5,092,274 and 5,113,797 show similar flood-type feeders.
The feeder described in the co-assigned U.S. Pat. No. 5,462,017, which is commercially sold under the trademark HI-LO, was introduced to overcome certain shortcomings of such flood-type feeders by providing a feed pan which may be selectively adjusted between a shallow pan position in which the young chicks may more readily see the feed presented within the feed pan thus eliminating the need for flooding the feed pan with feed. By eliminating the need to flood the feed pan with excess feed which was oftentimes wasted or became spoiled before it was consumed with the birds, it was found that the birds actually matured in less time (the grow out period was shortened) and less feed was required to raise a bird to its target market weight. In the use this feeder, upon the young chicks growing in height a sufficient amount (usually at about 10 days into the growth cycle), the feeders would be adjusted from the above-described shallow depth feed pan position to a deeper depth position such that the increased height of the rim of the feed pan would better contain the feed and would prevent the now larger birds from wasting the feed by raking or billing the feed from the feed pan which would be then dropped onto the floor of the poultry house and wasted.
As will be noted in many of the above-noted patents, these feeders are so-called grill-type feeders because they have a grill (of either wire or plastic construction) joining the outer margin of the feed pan to the central drop tube. While in many instances these grills do serve a useful function (i.e., they prevent excessive numbers of birds from attempting to feed from a single feeder at the same time and the spacing of the grill bars may be preset in breeding poultry houses such the cockerels which have larger heads are prevented from feeding from feeders intended for the hens), there were many instances where a grilless feeder would be desirable. It will be noted that if a grill-less feeder is provided, the amount of feed and the number of birds may maximized for each feeder. This translates to possibly fewer feeders being required to support a flock within a poultry house and in more feed being presented to the birds.
For larger birds, such as adult turkeys, it is important that the feeder present the maximum amount of feed and that the feeder be of rugged and simple construction so as to have a long service life within the poultry house.